Payment Integration System (US-Based)

Tech Stack: Angular · ASP.NET Core Web API · MS SQL Server

Overview

Worked on the continuation and enhancement of an existing multi-channel payment integration system for a US-based client. The platform enables secure digital payments across banking and mobile money providers in Ghana and South Africa, with added support for new payment features and improved transaction reliability.

Key Contributions

• Took ownership of an existing payment platform, extending functionality without disrupting live transactions.

• Integrated and enhanced payment APIs for Ecobank, MTN MoMo, and Vodacom M-Pesa, aligning with provider-specific protocols and callback flows.

• Added QR-based payment capabilities, expanding supported payment initiation methods.

• Implemented recurring billing and subscription logic, including status tracking and failure handling.

• Enhanced payment request workflows for improved transaction initiation and monitoring.

• Extended Angular front-end modules for transaction creation, real-time status tracking, and history views.

• Improved ASP.NET Core Web APIs for payment orchestration, validation, and secure processing.

• Strengthened asynchronous callback handling and reconciliation using MS SQL Server.

• Resolved production issues and optimized transaction flows to improve system stability.

Impact & Results

• Successfully extended an existing payment system with new payment channels and features.

• Improved transaction consistency, traceability, and reliability in a live financial environment.

• Supported scalable payment operations across multiple countries and providers